There is known a facsimile apparatus in which scanned image data is once stored in a semiconductor memory (hereinafter abbreviated to a “memory”), and after a series of scanning processes is completed, the image data is sequentially read out from the memory and is transmitted to a specified transmission partner. Hitherto, as the facsimile apparatus, there is known one provided with an image reading device including an ADF (Auto Document Feeder) to transfer a document from an input tray through a transfer path to an output tray. In addition, as the ADF, in JP-A-6-85649 to scan images recorded on two sides of a first side (front side) and a second side (back side) of a document in a series of document transfer operations, the transfer direction of the document is reversed in the transfer process of transferring the document from the input tray through the transfer path to the output tray, and the transfer for the two-sided scanning of the document is performed.
In the facsimile apparatus, in the case where the document has images on two sides and the images of the document are read out and are transmitted to the transmission partner, since the transfer direction of the document is reversed, the directions of the first side image (front side image) and the second side image (back side image) are different from each other by 180°.
There is proposed a digital image forming apparatus in JP-A-152894 in which an electric sort function is provided in which image data for plural pages are stored in a memory and the image data is repeatedly and sequentially read out from the memory so that sort is performed, and in the case where the memory free capacity becomes a specified capacity or less, the data amount of a read image is reduced by performing a processing to reduce the gradation per pixel.